摘要
为了探讨鄂尔多斯盆地榆林—绥德地区山西组山2段天然气运移动力和天然气分布之间的关系,通过真实气体状态方程求取典型井的生烃膨胀力,结合地层破裂压力系数确定烃源岩层古压力。依据砂岩包裹体恢复的成藏时期古流体压力为储层古压力,通过计算源储剩余压差分析天然气的运移动力。研究表明:陕142井上古生界由于生烃膨胀,煤层的古压力系数达1.93~1.96,可使煤层破裂;研究区山2段源储剩余压差平均5.99 MPa,源储剩余压差和含气饱和度之间呈明显的正相关性;该区山2段天然气在源储剩余压差作用下从烃源岩垂向运移至致密储层,具有就近聚集成藏特点。
In order to understand the relationship between migration force and distribution of natural gas of the second member of Shanxi formation in Yulin-Suide area,Ordos Basin,the paleopressure of hydrocarbon source rock in the study area was determined based on the hydrocarbon-generating expansion force of typical well calculated by the state equation of real gas and formation fracture pressure coefficient. Taking the fluid pressure in hydrocarbon accumulation periodrecovered by the fluid inclusion in sandstone as the paleopressure of hydrocarbon source rock,the migration force of natural gas was analyzed by calculating the residual pressure difference between source rock and reservoir. The research result shows that,the paleopressure coefficient of the Upper Paleozoic coal seam of well Shaan142 reaches to 1. 93 ~ 1. 96,which can make the coal seam crack. The residual source-reservoir pressure difference in the Shan 2 member of the study area is 5. 99 MPa,and there is a clear positive correlation between the residual source-reservoir pressure difference and gas saturation. The natural gas in the Shan 2 member migrated vertically from source rock to tight reservoir under the residual sourcereservoir pressure difference,and accumulated nearby.
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2018年第1期1-6,共6页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家科技重大专项"鄂尔多斯盆地天然气富集规律
目标评价与勘探关键技术"(2011ZX05007-004)
国家自然科学基金"鄂尔多斯盆地上古生界致密砂岩气成岩
成藏耦合机理研究"(41372148)
陕西省教育厅油气成藏地质学重点实验室项目(16JS088)
西安石油大学青年科技创新基金项目(2015BS07)
关键词
生烃增压
剩余压差
致密砂岩
上古生界
鄂尔多斯盆地
hydrocarbon-generating pressurization
residual pressure difference
tight sandstone
Upper Paleozoic
Ordos Basin
